Same here. Using Xubuntu 12.10 (64bit), geforce 8600m gt, 2GB Ram, nvidia 310.19.Under Windows XP with nvidia 266 driver Trine 2 runs smooth with middetail and a resolution of 1280x800. Under Xubuntu i set the Game to lowdetail and 1024x768, but it still is stuttering.

Ok. Now i followed the "Steam for Linux Limited Beta Release Notes" Thread from Frank and turned off the Sync to VBlank in the NVIDIA X Server Settings. After that the overall GL Peformance was better. Now some Games run with the same speed as they under Windows does (for example: Shatter, Amnesia, Vessel, Limbo), some Games are a bit slower, like Torchlight. Trine 2 also runs faster now than before, but it still is much slower as under windows, i can play it now nearly smooth with 1024x768 and very low details.

Whether Community In-Game is disabled or enabled doesn't seem to matter …With a little bit higher frame rate it would actually render Trine 2 (1.19) properly with maximal settings in 1920:1080 (16:9) on this machine. No FPS cap (whether Sync to Vblank is enabled or not doesn't matter, and the game launcher have Vsync disabled). I slapped a screenshot of the launcher here: http://imgur.com/bccwX

I have very similar problems to Olorin, above, as well as similar hardware (Geforce GTX 260 mobile).

Proc: Core i7Drivers: 310.14Ubuntu 12.04

So far other 3d games seem to work fine, though this is the first steam game I've tried (though since I disabled in-game steam community for it, I don't think that is the issue). Also, I disabled V-Sync.

Try this:Create Trine 2 desktop shortcut then reboot PC. Don't launch steam at start just run game from Your desktop. It works for me. When i run Steam and then Trine 2 from shortcut then game is slow again. To fix this i must reboot PC or log out from my linux account. The game works fine only when i run directly from desktop shortcut without runing steam in background. Can anyone confirm this method?